Schwarzenegger Maid-Mistress Mildred Patty

Mildred “Patty” Baena, the housekeeper who had a child with Arnold Schwarzenegger, is breaking her silence on her affair with the disgraced Governator — and Maria Shriver’s reaction to the revelation of Mildred and Arnie’s lovechild — in a new interview with Britain’s Hello! Magazine.

At first believing that her ex-husband was the child’s father, Mildred says she only began to realize Joseph’s true parentage when the blond-haired, blue-eyed boy became more and more of an Arnold doppelganger as the years went by.

“It was as Joseph grew and I started to see the resemblance that I wondered – but It became more apparent as time went on,” she says. “I knew Arnold was the father, and maybe as Joseph got older and began to look like him, he [Arnold] wondered. But he never said anything to me.”

Baena – who worked as a housekeeper for the couple for 20 years – never confessed her son’s paternity to Arnold — or anyone else — following a brief fling with the Terminator star back in the late ’90s. Maria, nevertheless, became suspicious that her husband of a quarter century had secretly stepped out with the help after other staffers pointed out similarities between the now 13-year-old and the bodybuilding legend. Patty “broke down” after being cornered by Maria.

“Last summer I brought Joseph over to the house. Until then, he hadn’t been around very much. After that, people in the house started whispering about how much they looked like each other,” the Guatemalan-born housekeeper, 50, explains. “Maria would ask if I needed to talk to her and I kept saying no. She would say things like, ‘I’m here if you need to talk.’ I sensed something was up. I have so much love and respect for Maria. Finally, she asked point blank. Maria asked me directly if Joseph was Arnold’s son and I just broke down. I dropped to my knees and I was crying saying that yes he was and I was so sorry.”

To Mildred’s shock, Maria didn’t break out a bat and try to play a game of “Whoop Dat Trick” on her face after learning of her indiscretion with Arnold. Instead, the former NBC journalist comforted the housekeeper, even urging her not to retire from her job until after the holiday season.

“She was so strong. She cried with me and told me to get off my knees. We held each other and I told her it wasn’t Arnold’s fault, that it takes two. Since I was retiring soon, I said I would pack and leave right away, but she said to stay until after the holidays.”

Now the retired domestic employee hopes the couple – who have hired divorce attorneys to hash out the details of their official split – manage to reconcile and save their marriage.

“He’s a good man and I know he’s suffering too. He loves Maria. I hope with time they work things out.”

Joseph only learned last year that the man he grew up believing was his mother’s boss is actually his dad. As kids often do, the rambunctious boy took the news in stride. “Cool!” he exclaimed after his grandmother broke the news to him. Mildred says Joseph’s looking forward to getting to know his father.